Attenuator



April 1948- Q E. DOUCETTE 2,439,160

ATTENUAI'OR Filed Feb. 26, 1945 E i 2 Ma 0.0 F21 e.

-/ ND DoucETTE- INVENTOR E 5 BY ATTORNEY Patented Apr. 6, 1948 ATTENUATOR Edmund Doucette, Newark, N. J., assignor to The Daven Company, Newark, N. .L, a corporation of New Jersey Application February 26,1945, Serial No. 579,829 3 Claims. (01. 201-55) This invention. relates to attenuators as used in the communications field, and more particularly to multiple unit attenuators.

'An object of the present invention is to provide an improved construction of multiple unit attenuators which embodies novel features of construction and arrangement of parts-resulting in a reduction of the manufacturing costs of the device, a simplification of the construction of multiple unit attenuators, and provides a structure wherein single unit attenuators may be quickly, easily, and inexpensively combined to form multiple unit structures, thereby permitting production manufacture of single unit attenuators or their parts which with slight alterations may be combined into multiple units of any desired degree of multiplication of the single unit.

Another object of the present invention is the provision in multiple unit attenuators of a novel construction or the movable contact operating shafts which permits quick and easy connection of the shafts of single units, making up the multiple unit, for synchronous operation of the shafts and movable contacts, and which further implifies the assembly of the parts of the attenuator.

A further object of the present invention is to provide an attenuator so constructed and designed as to permit quick and easy inspection, cleaning, or repair of the switch contact members or other internal parts without the need of removing the front unit from its position on an instrument panel, and one which also is dust tight thereby providing improved electrical shielding and further providing protection to the switch rotor and contacts of the front unit of the attenuator.

With these and other objects in view, as may appear from the accompanying specification, the invention consists of various features of construction and combination of parts, which will be first described in connection with the accompanying drawings, showing an attenuator of a preferred form embodying the invention, and the features forming the invention will be specifically pointed out in the claims.

In the drawings:

Figure 1 is a side elevation of a multiple unit attenuator constructed in accordance with the present invention.

Figure 2 is a longitudinal section through the attenuator.

Figure 3 is a cross section taken on the line 3-3 of Figure 2.

Figure 4 is a detail fragmentary section oi a part of the attenuator assembly.

Figure 5 is a detail cross section taken on the line 5-5 of Figure 2.

Figure 6 is a detail section taken on line 6-6 of Figure 1 showing the manner of fastening together the housings.

Referring more particularly to the drawings, the improved multiple unit attenuator is an adaptation of the single unit attenuator as shown in the co-pending application of John P. Smith, Jr., Serial No. 562,989, filed the 11th day of November, 1944, with some changes and modifications thereto to adapt the single units for connection in a multiple unit.

In the drawings, a multiple unit attentuator is illustrated embodying two single units in cont bination, but it is to be, understood that any number of the single units may be coupled together in the manner of the present invention, as may be desired or required, without departing from the spirit of the present invention.

Each of the single unit attenuators comprises a housing i in the form of a cylindrical shell which has the electric current resisting means 2 therein, the stationary contacts 3 being carried by the insulating plate 4. The attenuators each include movable contacts 5 which cooperate with the stationary contacts 3 as is usual in attenuator structures. The movable contact -5 of the unit to is carried by an operating shaft 6 which extends axially through the casing l and has a turning knob l upon its end which projects out of the housing i. The shaft 6 has a detent gear 8 thereon which is of the same construction as the detent gear shown in the afore-mentioned application 01' John P. Smith, Jr. The detent gear 8 co-operating with the dished closure plate 9 which is rigidly secured to the housing i limits the degree of insertion of the shaft 6 through the electrical resistance mechanism 2 so as to insure proper positioning of the movable contact 5 and of the placing of the proper tension upon the spring fingers ill of the movable contact when the parts of the attenuator are assembled.

As clearly shown in Figure 2 of the drawings, the shaft 6 extension beyond the collar II, by means of which the movable contact 5 is attached to the shaft 6, and the portion of the shaft 6 extending inwardly beyond the inner end of the collar H is cut away to form a semi-cylindrical section I2, the fiat surface H of which engages the fiat surface I5 of the cut away section iii of the movable contact operating shaft ll of the single unit 2a. A guiding and retaining sleeve I8 is mounted about the shaft [1, is pinned thereto, and extends over the cutaway end of the shaft, the. end oi the sleeve being flush with th aseaieo inner end or the cut away portion or the i so that when the two units to and ass :21 bled in a multiple unit attenuator as thorn-i in section of Figure 2 of the drawings, the two inner engaging flattened ends of the shafts 6 and ill will be held in. proper contact with each other, and the shafts will be connected for synchronous movement which will provide synchronous move=- merit of the movable contacts 5 of the sections to and 2c.

lhe housing i of the section do: has its outer end closed by a removable closure cap it). The open end of which slips over the outer end of lit) the housing 6 as clearly shown in Figure 2, and

is held in place by means of a pin to which on tends through aligning openings iii in the lions mg i and the closure cap it. The pin to is carried by a fiat spring 82, one end of which is se-= cured to the inner surface of the housing 2. A threaded stud 26 is attached to the flat spring 32 intermediate its attached end and the pin to and extends through a bayonet slot in the cap it and has a nut 2t threaded thereon. When the cover it is connected to the housing i, the g nut to is threaded outwardly as shown in Figure 6 so as to permit movement of the stud Ed in the bayonet slot 25 to allow the pin St to pass through the opening tit under the spring action of the flat spring After the pin is in place, the nut to is tightened against the outer surface of the cover it which loclzs the pin in place and the cover cap it on the housing. Upon dis connection of the cover it from the housing i,

the nut is threaded outwardly on the stud, and

by forcing the nut and stud inwardly the spring 32 will give and move the pin So out of the holes iii.

The inner end of housing l of the unit 2a is closed by the rigidly attached closure plate 22;

to accommodate the movable contact 5 of unit to.

The coupling member 23 is connected to housing i of unit la by a structure of the same construc-= tion as that employed in connecting the cover cap it to the housing i of unit to.

Each of the units to and 2a include a terminal block 23 which, like in the Smith application above-referred to, is slidably carried by the housing 5 of the unit. In the multiple unit attenuator, the terminal blocks 28 are held against longi-= tudinal movement in one direction by contact with the switch panels ll of the units and by contact with the closure plates 9 and 22 in the other direction, as clearly shown in Figure 2 or the drawings.

By the manner of cutting the shafts t and ill to provide the interengaging semi-cylindrical ends of each shaft, and the provision of the guid ing and retaining sleeve it, the two single units to and to will and must be in proper synchronized connection for synchronous movement when the shafts are coupled together and when the units are connected to form the single multiple unit device.

It will be understood that the invention is not to be limited to the specific construction or arrangement of \parts shown, but that they may be widely modified within. the invention defined by the claims.

What is claimed is:

a multiple attenuator, a of single each enclosing an annular ring like connecting member rigidly connected to the housing ct one oi said single units and removably engaging the housing of the other single unit in overlapping engagement, to prevent accidental displacement oi said coupling member and the housing which it de tachably engages, terminal blocks slidably car= ried by said housing, and means to prevent longitudinal movement oi the terminal blocks.

2. in a multiple unit attenuator, a plurality of single units each having an enclosing housing, an annular ring like connecting member rigidly connected to the housingoi one of said single units and removably engaging the housing oi the other single unit in overlapping engagement, means to prevent accidental displacement of said coupling member and the housing which it detachably engages, each of said single units in cluding electrical resistance means including a movable contact unit and an operating shaft for its movable contact umt, said shafts having their inner ends cut away to provide send-cylindrical inter-engaging coupling sections whereby when the single units are assembled in end to end relation in a multiple unit attenuator the hat sur= faces of the shafts of the units will be in fiat overlapping engagement for connecting the units for synchronous movement.

3. In a multiple unit attenuator, a plurality of single units each having an enclosing housing, an annular ring like connecting member rigidly connected to the housing of one of said single units and removably engaging the housing of the other single unit in overlapping engagement, means to prevent accidental displacement of said coupling member and the housing which it de= tachably engages, and each of said single units including electrical resistance means including a movable contact unit and an operating shaft for its movable contact unit, said shafts having their inner ends cut away to provide inter=en= gaging coupling sections whereby when the single units are assembled in end to end relation in a multiple attenuator the fiat surfaces or the shafts of the units will be in flat engagement for connecting the units for synchronous movement, and a guiding retaining sleeve about the coupling end of one of said shafts and overlapping the engaging semi-cylindrical coupling portions of the shafts to retain the inner engaging shaft ends in proper engagement.

EDMFUND DOUCETTE.

The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,466,293 Brooks Aug. 28, 1923 1,613,606 Flammer Jan. 11, 1927 1,695,875 Aiken Dec. 18, 1928 1,987,118 Lodge Jan. 8, 1935 2,120,651 Schellenger June it, 1938 2,207,821 Robinson July 16, 1940 2,401,037 Arvin May 28, 1946 FOREIGN PATENTS Number Country Date 49,438 Netherlands Sept. 17, 1949 

